Structure-guided immunogens to elicit pan-coronavirus B cell responses

结构引导免疫原引发泛冠状病毒 B 细胞反应

• 批准号: 10420514
• 负责人: Aaron Gregory Schmidt
• 金额: $ 193.41万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-02 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10420514
• 关键词: 2019-nCoV; ACE2; Antibodies; Antigens; Avidity; B-Cell Antigen Receptor; B-Lymphocytes; Binding; Biochemical; Biological Assay; Biophysics; Cells; Chad; Complex; Coronavirus; Cryoelectron Microscopy; Development; Engineering; Epitopes; Evaluation; Frequencies; Future; Genes; Glycoproteins; Humoral Immunities; Immune; Immune response; Immunity; Laboratories; Link; Masks; Merbecovirus; Middle East Respiratory Syndrome Coronavirus; Molecular; Molecular Conformation; Monoclonal Antibodies; Output; Polysaccharides; Protein Binding Domain; Proteins; Recombinants; Recording of previous events; Role; SARS coronavirus; Sarbecovirus; Serology; Site; Structure; Surface; System; Vaccinated; Vaccinee; Vaccines; Variant; Vesicular stomatitis Indiana virus; Viral; Viral Vaccines; Virus; X-Ray Crystallography; base; betacoronavirus; coronavirus receptor; cross reactivity; crosslink; design; glycosylation; human subject; immunogenicity; interest; lumazine; nanoparticle; next generation; non-Native; novel coronavirus; pandemic disease; rational design; receptor; receptor binding; reconstruction; response; scaffold; universal coronavirus vaccine; vaccine development; vaccine formulation; vaccine platform; vector

Project Summary The global pandemic caused by Severe Acute Respiratory Syndrome virus 2 (SARS-CoV-2) coronavirus (CoV) has highlighted the need to develop next-generation viral vaccines that offer protection against future Sarbecoviruses and Merbecoviruses of concern. One approach is to implement structure-based immunogen design strategies that elicit humoral responses to conserved sites on the surface-exposed spike (S) viral glycoprotein. Potential sites include the receptor binding domain (RBD) and the receptor binding motif (RBM) required for viral entry. Other conserved sites on S, outside the RBD, may also be targets of both neutralizing and non-neutralizing responses offering broad CoV protection. Project 1 will combine computational, structural, biophysical, and single B cell analyses to design S and RBD immunogens that elicit broad-spectrum humoral immunity against CoVs. Based on evolutionary analysis of CoV sequences, it is unlikely that a single antigen will confer broad enough immunity against the entire Betacoronavirus genus; we therefore anticipate generating a polyvalent S or RBD containing vaccine (with Project 3). Initially, we prioritize ACE2-receptor using CoVs as a proof-of-concept but envision that our design principles can be extended to other emerging CoVs where ACE2 is not the receptor. The Schmidt laboratory will implement structure-guided immunogen design strategies to focus immune responses towards conserved epitopes on the RBM and RBD. We will use heterologous CoV RBDs as molecular scaffolds to present selected ACE2-binding CoV RBMs and further immune focus using engineered glycans to mask non-conserved epitopes. The Scheuermann laboratory will use ancestral reconstructions to identify extant CoVs as additional S-based immunogens. The Ellebedy laboratory will isolate monoclonal antibodies (mAbs) from naturally infected, vaccinated, or naïve human subjects to define CoV cross- reactive, conserved epitopes on S recognized by neutralizing and non-neutralizing mAbs. We will define the breadth of mAb cross-reactivity, cross-neutralization, and effector functions (with Project 3). The Fremont laboratory will perform structural analyses by X-ray crystallography and cryo-electron microscopy (Fremont laboratory) of the isolated mAbs to define targeted epitopes on S; this information will aid in iterative immunogen optimization to elicit responses to these newly defined, cross-reactive epitopes. The output of Project 1 will be optimized RBD and S genes to transfer to Project 3 for vaccine formulation in VSV or ChAd vaccine platforms.

项目概要 由严重急性呼吸系统综合症病毒 2 (SARS-CoV-2) 冠状病毒 (CoV) 引起的全球大流行 强调需要开发下一代病毒疫苗来预防未来 值得关注的 Sarbecoviruses 和 Merbecoviruses。一种方法是实施基于结构的免疫原 设计策略，引发对表面暴露的刺突（S）病毒保守位点的体液反应 糖蛋白。潜在位点包括受体结合域 (RBD) 和受体结合基序 (RBM) 病毒进入所需。 S 上 RBD 之外的其他保守位点也可能是中和的目标 和非中和反应提供广泛的冠状病毒保护。项目 1 将结合计算、结构、 生物物理和单 B 细胞分析，设计可引发广谱体液免疫的 S 和 RBD 免疫原 对冠状病毒的免疫力。根据 CoV 序列的进化分析，单一抗原不太可能 赋予针对整个乙型冠状病毒属的足够广泛的免疫力；因此，我们预计会产生一个 含有多价 S 或 RBD 的疫苗（与项目 3 一起）。最初，我们优先考虑使用 CoV 作为 ACE2 受体 概念验证，但设想我们的设计原则可以扩展到其他新兴的冠状病毒，其中 ACE2 不是受体。施密特实验室将实施结构引导的免疫原设计策略 将免疫反应集中于 RBM 和 RBD 上的保守表位。我们将使用异源冠状病毒 RBD 作为分子支架来呈现选定的 ACE2 结合 CoV RBM 并使用进一步的免疫焦点 工程聚糖来掩盖非保守表位。苏门实验室将使用祖先的 重建以将现有的 CoV 识别为额外的基于 S 的免疫原。 Ellebedy 实验室将隔离 来自自然感染、接​​种疫苗或未接触过的人类受试者的单克隆抗体 (mAb)，用于定义 CoV 交叉抗体 S 上的反应性保守表位可被中和性和非中和性单克隆抗体识别。我们将定义 mAb 交叉反应、交叉中和和效应器功能的广度（与项目 3 一起）。弗里蒙特酒店 实验室将通过 X 射线晶体学和冷冻电子显微镜（弗里蒙特）进行结构分析 实验室）分离的单克隆抗体，以确定 S 上的目标表位；该信息将有助于迭代免疫原 优化以引发对这些新定义的交叉反应表位的反应。项目 1 的输出将是 优化 RBD 和 S 基因，转移至项目 3，用于 VSV 或 ChAd 疫苗平台中的疫苗配制。